Recent aspects in the development of a closed ecologic system.

T H E C O N C E P T of a closed ecologic .system in its entirety has existed for a number of years in the mind .of one of our foremost scientists in the field of Space Medicine. Dr. Hubertus Strughold had envisioned man on extended flights into space, his respiratory requirements to be met by an appa.ratt~s termed a photosynthetic gas exchanger. T,his brilliant idea began to assume its place in reality when Doer:or Strughold as Chief of the Department o,f Space Medicine, Sc,h,ool .of Aviation Medicine, contacted Dr. Jack Myers and a young graduate student, J. Nell Phillips, at the University of Texas regarding ~he project on May 14, 1952. On May 17, 1952, J. Nell Phillips, who recently joined the School .of Aviation Medicine staff, was en,co,uraged by Doctor Strughold's enthusiastic discussion and submitted a research proposal entitled "Development of Balanced Respiratory Systems between Plants and Animals for Closed Systems," a proposal which is now recognized as the first known written document concerning the use of a photosynthetic gas exchanger. In 1960, the 'same requirements for a closed system exist as in 1952. The original justification for the pro,blem written in May 19'52, is still applicable